1. Field of the Invention
The present invention relates generally to an internal antenna for mitigating the effect of electromagnetic waves on a human body using coupling, and, more particularly, to an internal antenna capable of mitigating the effect of electromagnetic waves on a human body using coupling, which transfers current components from an antenna pattern part to a conductive conductor pattern formed in a predetermined pattern on one side surface of a cover which covers the antenna pattern part, thereby blocking electromagnetic waves directed at a human body while maintaining similar radiation performance.
2. Description of the Related Art
As concerns about the effects of electromagnetic waves on a human body increase, international organizations have established standards regarding Specific Absorption Rates (SARs) of the electromagnetic waves for a human body. Accordingly, the types and number of mobile phones to which the SARs for a human body are being applied are increasing. The development of antennas having performance satisfying the above-described standards is impending.
FIG. 1 is a diagram showing the construction of conventional internal antenna. As shown in FIG. 1, the conventional internal antenna includes an antenna pattern part 20 composed of a radiation element 21 and a carrier 22 on a Printed Circuit Board (PCB) 10, and a cover 30 for covering the antenna pattern part 10 is made of plastic resin such polycarbonate (PC) material, so that electromagnetic waves directed at a human body cannot be blocked using only the antenna pattern part 20 composed of the radiation element 21 and the carrier 22.
FIG. 2A is a graph illustrating the Voltage Standing Wave Ratio (VSWR) of a conventional internal antenna, and FIG. 2B is a graph illustrating a radiation pattern in the PCS 1900 (1850 MHz˜1990 MHz) band which is the higher of the frequency bands of the conventional internal antenna. As shown in FIG. 2A, in the conventional internal antenna, resonant frequencies are generated in the GSM 850 (824 MHz˜894 MHz) band and the PCS 1900 (1850 MHz˜1990 MHz) band. Here, a radiation pattern in the PCS 1900 (1850 MHz˜1990 MHz) band, which is a higher frequency band, is generated such that energy density is highest within the range of −60 to 0 degrees within which electromagnetic waves generated by the internal antenna are directed at a human body, as shown in FIG. 2B. Accordingly, the conventional internal antenna in which the cover 30 for covering the antenna pattern part 20 is made of plastic resin has a problem in that it cannot block electromagnetic waves directed at a human body.